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4.2. General procedure for the synthesis of amidine
derivatives (3a–i)
50.98; H, 4.57; N, 18.30; S, 10.45. Found: C, 50.59; H,
4.40; N, 18.15; S, 10.63.
4.2.1. Synthesis of N-(phenyl sulfonamido)picolinamidine
(3a). Sodium metal 23 mg was dissolved in 20 ml abso-
lute methanol and was labelled as sodium methoxide
solution in methanol. 2-Cyanopyridine (0.104 g;
1 mmol) was dissolved in absolute methanol (10 ml)
and to it was added sodium methoxide solution (2 ml)
prepared above, the reaction contents were stirred at
room temperature for 4 h and then benzenesulfonylhyd-
razide (0.172 g; 1 mmol) was added to it. The reaction
contents were heated under reflux for 4 h. Solvent was
removed under reduced pressure and to the residue left
behind was added distilled water (15 ml) and the solid
separated out was filtered, washed with water and air-
dried to give crude product, which was purified by crys-
tallization from methanol to give pure product 3a. Yield
0.180 g, (65%); mp 130 ꢁC; IR (KBr) mmax: 3369 and
4.2.4. N-(Phenyl sulfonamido)isonicotiamidine (3d). Sol-
vent of crystallization: MeOH; 0.110 g (40%); mp
180 ꢁC; IR (KBr) mmax: 3469 (NH), 1650 (C@N), 1546
1
(Ar) cmꢀ1. H NMR (300 MHz, DMSO-d6 + CDCl3),
6.00 (br s, 2H, NH, NH, exch), 7.49–7.59 (m,
J = 7.2 Hz, 5.7 Hz, 5H, 3H (Ar) + 2H (Py)), 7.92–7.99
(t, J = 7.2 Hz, 2H, Ar), 8.54–8.56 (t, J = 5.7 Hz, 2H,
Py), 9.30 (br s, 1H, NH, exch). FAB-MS m/z 277
+
NHNH
(MH+, 100%), m/z 276 (M+, 15%), 135 (N
,
NH
+
N
17%), 105
(
,
5%). Anal. Calcd for
NH
C12H12N4O2S: C, 52.17; H, 4.34; N, 20.28; S, 11.59.
Found: C, 51.72; H, 4.03; N, 19.81; S, 11.14.
4.2.5. N-(4-Methyl phenyl sulfonamido)isonicotiamidine
(3e). Solvent of crystallization: MeOH; 0.143 g (49%);
mp 197–200 ꢁC; IR (KBr) mmax: 3458 and 3352 (NH),
3211 (NH), 1635 (C@N), 1577 and 1474 (Ar) cmꢀ1
.
1H NMR (300 MHz, DMSO-d6 + D2O) d: 7.32 (q,
J = 5.4 Hz, 1H, Py), 7.49–7.69 (m, J = 8.1 Hz, 7.5 Hz,
5.7 Hz, 4H, 2H (Ar) + 2H (Py)), 7.94–8.01 (dd,
J = 8.1 Hz, 7.5 Hz, 3H, Ar), 8.51 (d, J = 4.0 Hz, 1H,
Py). FAB-MS m/z 277 (MH+, 100%), 276 (M+, 12%).
Anal. Calcd for C12H12N4O2S: C, 52.17; H, 4.34; N,
20.28; S, 11.59. Found: C, 52.00; H, 4.21; N, 20.51; S,
11.31.
1644 (C@N), 1602 (Ar) cmꢀ1 1H NMR (300 MHz,
.
DMSO-d6 + CDCl3) d: 2.42 (s, 3H, CH3), 6.14 (br s,
2H, NH, NH, exch), 7.31–7.34 (d, J = 8.1 Hz, 2H
(Ar)), 7.58–7.60 (dd, J = 6.0 Hz, 2H, (Py)), 7.82–7.85
(d, J = 8.1 Hz, 2H, Ar), 8.54–8.56 (t, J = 6 Hz, 2H,
Py), 9.30 (br s, 1H, NH, exch). FAB-MS m/z 291
+
(MH+, 100%), 290 (M+, 12%), 135 (N
NHNH, 25%),
Similarly were synthesized compounds 3b–i.
NH
+
N
105 (
, 22%). Anal. Calcd for C13H14N4O2S:
4.2.2. N-(4-Methyl phenyl sulfonamido)picolinamidine
(3b). Solvent of crystallization: MeOH; 0.141 g (48%);
mp 175 ꢁC; IR (KBr) mmax: 3454 and 3347 (NH), 1645
NH
C, 53.79; H, 4.82; N, 19.31; S, 11.03. Found: C, 53.54;
H, 5.03; N, 19.52; S, 10.84.
(C@N), 1592 and 1470 (Ar) cmꢀ1
.
1H NMR
4.2.6. N-(4-Methoxy phenyl sulfonamido)isonicotiamidine
(3f). Solvent of crystallization: MeOH; 0.138 g (45%);
mp 210 ꢁC; IR (KBr) mmax: 3433 and 3347 (NH), 1648
(300 MHz, DMSO-d6 + CDCl3) d: 2.40 (s, 3H, CH3),
6.12 (br s, 2H, NH, NH, exch), 6.37 (br s, 1H, NH,
exch), 7.29 (t, J = 8.1 Hz, 7.9 Hz, 6.9 Hz, 3H, 2H
(Ar) + 1H (Py)), 7.62 (m, J = 6.9 Hz, 1H, (Py)), 7.87
(d, J = 8.1 Hz, 2H, Ar), 7.95 (d, J = 7.9 Hz, 1H, Py),
8.48 (d, J = 4.5 Hz, 1H, Py). FAB-MS m/z 291 (MH+,
(C@N), 1598 and 1495 (Ar) cmꢀ1
.
1H NMR
(300 MHz; DMSO-d6 + CDCl3) d: 3.86 (s, 3H, OCH3),
6.05 (br s, 2H, NH, NH, exch), 6.97–7.02 (m,
J = 6.9 Hz, 2H, Ar), 7.57–7.61 (q, J = 4.6 Hz, 2H
(Py)), 7.87–7.9 1 (m, J = 6.9 Hz, 2H, Ar), 8.55–8.57 (q,
J = 4.8 Hz, 2H, Py), 9.13 (s, 1H, NH, exch). FAB-MS
m/z 307 (MH+, 100%), m/z 306 (M+, 7%), 228
+
NHNH
100%), m/z 290 (M+, 13%), 135 (
, 15%), 105
NH
N
+
(
, 20%). Anal. Calcd for C13H14N4O2S: C,
NH
N
NH
H3CO
S
O2
NH
HN
NH
S
O2
N
3
(
, 8%), 226 (H CO
,
53.79; H, 4.82; N, 19.31; S, 11.03. Found: C, 53.74; H,
4.49; N, 19.25; S, 10.65.
N
+
+
+
NHNH
+
N
50%) 135 (N
, 16%), 105 (
, 18%).
NH
NH
4.2.3. N-(4-Methoxy phenyl sulfonamido)picolinamidine
(3c). Solvent of crystallization: MeOH; 0.180 g (59%);
mp 140 ꢁC; IR (KBr) mmax: 3362 and 3190 (NH), 1650
Anal. Calcd for C13H14N4O3S: C, 50.98; H, 4.57; N,
18.30; S, 10.45. Found: C, 50.49; H, 4.29; N, 18.17; S,
9.95.
(C@N), 1592 and 1497 (Ar) cmꢀ1
.
1H NMR
(300 MHz; DMSO-d6 + CDCl3) d: 3.87 (s, 3H, OCH3),
6.12 (br s, 2H, NH, NH, exch), 7.00 (q, J = 8.7 Hz,
2H, Ar), 7.32 (t, J = 6.9 Hz, 1H (Py)), 7.47 (br s, 1H,
NH, exch), 7.67 (m, J = 6.9 Hz, 1H, Py), 7.97 (m,
J = 8.7 Hz, 3H, Ar), 8.52 (d, J = 4.5 Hz, 1H, Ar).
FAB-MS m/z 307 (MH+, 100%), 306 (M+, 7%), 171
4.2.7. N-(Phenyl sulfonamido)pyrazine-2-carboxamidine
(3g). Solvent of crystallization: MeOH; 0.145 g (52%)
mp 205 ꢁC; IR (KBr) mmax: 3324 (NH), 1615 (C@N),
1515 (Ar) cmꢀ1
.
1H NMR (300 MHz, DMSO-
d6 + CDCl3) d: 6.25 (s, 2H, NH, NH, exch), 7.50–7.61
(m, J = 8.1 Hz, 3H, Ar), 7.97–8.00 (d, J = 8.1 Hz, 2H,
Ar), 8.45 (d, 1H, Pyr), 8.54 (d, 1H, Pyr), 9.20 (s, 1H,
Pyr), 9.53 (br s, 1H, NH, exch). FAB-MS m/z 278
(MH+, 55%), 277 (M+, 10%). Anal. Calcd for
+
NHNH
+
H CO
3
SO
(
(
2, 10%), 135 (
, 22%), 105
NH
N
+
, 21%). Anal. Calcd for C13H14N4O3S: C,
NH
N